This invention relates to user interface devices for personal computers and, more particularly, to foot-operated interface control devices for use with personal computers.
A number of different user-interface devices have been developed for video game applications running on a personal computer or dedicated game console apparatus such as joysticks and foot pedals. These devices permit users to control various input signals, which in turn control operation of the game or other program executing on the computer (e.g. a flight simulator). For example, foot pedal interface devices simulate the operation of a car in a car chase game by allowing the user to control the speed with a gas pedal and to control the braking functions with a brake pedal. In conjunction with a steering wheel input device, the user is provided with a simulation experience. The basic interoperability of these types of input devices with personal computers or dedicated game consoles is well known in the art. While various types of such user interfaces such as foot pedals exist, many of the user-interface devices fail to realistically simulate at a reasonable cost the sensation of foot pedals commonly found in vehicles and aircraft.
U.S. Pat. Nos. 5,237,891; 4,695,819; and 4,958,607 disclose foot pedal assemblies designed for application in full-size cars and trucks. The components utilized in these designs are too numerous and/or complex for practical application with personal computers. Likewise, the foot-operated electrical control device disclosed in U.S. Pat. No. 5,177,473 is designed for use in aircraft, also making it impracticable for application involving personal computers and video games due to its complexity and cost.
Therefore, it would be advantageous if a foot-actuated user interface device could realistically simulate foot pedal assemblies that are commonly used in full-size vehicles and aircraft while being both economical to manufacture and affordable to purchase.
U.S. Pat. No. 5,552,807 (incorporated herein by reference) discloses a foot pedal assembly for use with personal computers. The foot pedal in this invention pivots about a rotating gear located approximately midway along the length of the pedal. The user's foot must undergo essentially a rocking motion in order to activate the foot pedal assembly. Such a rocking motion is not an accurate simulation of pedals found in vehicles. Furthermore, since the rocking motion necessitates that the user's heel undergo vertical displacement rather than being substantially fixed (as with standard pedals found in vehicles), a heel rest is required in the design in order to counteract any tendency of the user's heel to shift with respect to the pedal during the rocking motion.
Therefore, it would be advantageous if the foot pedal assembly could accurately simulate the physical sensations associated with an actual pedal typically found in vehicles and aircraft in order to increase the level of realism experienced by the user during participation in the video game. It would also be advantageous if the foregoing could be accomplished without need for additional components such as a heel rest to retain the user's foot on the pedal.
Another foot pedal assembly of the prior art is illustrated in FIGS. 5 and 6 herein, and comprises a foot pedal 13, a base 21, an aft portion 41 of the base 21 and a single elongate vertical support member 15. The vertical support member 15 is attached at one end to the foot pedal 13 and attached at the other end to a gear mechanism that turns a potentiometer as the foot pedal is depressed, thus changing the electrical signal input to the computer (not shown). A generally downward force F2 directed at point P2 is imparted to the vertical support member 15 as the foot pedal 13 is depressed by the user's foot. However, this downward force F2 comprises both a vertical component F2.sub.V and a horizontal component F2.sub.H. Thus, as the foot pedal 13 is depressed, the horizontal component F2.sub.H of the downward force F2 causes the center of gravity of the foot pedal assembly to shift forward, resulting in the undesirable raising or tipping of the aft portion 41 of the base 21 vertically upward. The force F2 must be counterbalanced by pressure applied at point P3 to the aft portion 40 in order to prevent the base 21 from tipping, which of course is undesirable.
Furthermore, in depressing the foot pedal 13 of the prior art illustrated in FIGS. 5 and 6, the user's foot must slide backward (towards the user's heel) across the top of the foot pedal 13 if the user is to maintain his heel at center C1 in a stationary position with respect to the base 21. The action of the user's foot sliding backward across the top of the foot pedal 13 causes wear in the contact surfaces of the user's foot and foot pedal 13 as well as a perception of unresponsiveness by the user. The reason that the user's foot must slide across the foot pedal 13 is that an arc A2 which defines the travel of the foot pedal 13 during depression is not concentric with (i.e., does not have the same center as) a natural arc A1 made by the user's foot in depressing the foot pedal 13 while maintaining his heel in a substantially stationary position relative to the base 21. In fact a center C2 of the arc A2 made by the foot pedal 13 is substantially forward of the center C1 of the natural arc A1 made by the user's foot. The horizontal variation of the two centers C1 and C2 causes the average horizontal component F2.sub.H of the arc A2 made by the foot pedal 13 during depression to be much larger than the horizontal component of the natural arc A1 made by the user's foot. Thus, in order to compensate for the greater horizontal component F2.sub.H of the arc A2 made by the foot pedal which is directed forward, the user's foot must slide backward across the top of the foot pedal 13 in the direction shown by arrow AR1.
Therefore, it would be advantageous if depression of the foot pedal assembly would not cause the aft portion of the foot pedal assembly to tilt upwards. It would also be desirable if the foot pedal would naturally follow the arc made by the user's foot during depression thus eliminating the necessity that the user's foot slide across the foot pedal during depression.